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#include <QtGui>

#include "CodeHighlighter.h"

CodeHighlighter::CodeHighlighter(QTextDocument *parent)
    : QSyntaxHighlighter(parent)
{
    HighlightingRule rule;

	/*
	setKeywordFormat.setForeground(Qt::darkBlue);
    setKeywordFormat.setFontWeight(QFont::Bold);
    QStringList setKeywordPatterns;
    setKeywordPatterns << "\\bBOOL\\b" << "\\bN\\b" << "\\bZ\\b";

    foreach (const QString &pattern, setKeywordPatterns)
	{
        rule.pattern = QRegExp(pattern);
        rule.format = setKeywordFormat;
        highlightingRules.append(rule);
    }
	*/

    singleLineCommentFormat.setForeground(Qt::darkGreen);
    rule.pattern = QRegExp("//[^\n]*");
    rule.format = singleLineCommentFormat;
    highlightingRules.append(rule);

    multiLineCommentFormat.setForeground(Qt::darkGreen);

	stringFormat.setForeground(Qt::darkGreen);
    rule.pattern = QRegExp("\".*\"");
    rule.format = stringFormat;
    highlightingRules.append(rule);

    functionFormat.setFontItalic(true);
    functionFormat.setForeground(Qt::blue);
    rule.pattern = QRegExp("\\b[A-Za-z0-9_]+:");
    rule.format = functionFormat;
    highlightingRules.append(rule);

	mainKeywordFormat.setForeground(Qt::darkGray);
    mainKeywordFormat.setFontWeight(QFont::Bold);
    QStringList mainKeywordPatterns;
    mainKeywordPatterns << "\\bopns\\b" << "\\bvars\\b" << "\\beqns\\b";

    foreach (const QString &pattern, mainKeywordPatterns)
	{
        rule.pattern = QRegExp(pattern);
        rule.format = mainKeywordFormat;
        highlightingRules.append(rule);
    }

    commentStartExpression = QRegExp("/\\*");
    commentEndExpression = QRegExp("\\*/");
}

void CodeHighlighter::highlightBlock(const QString &text)
{
    foreach (const HighlightingRule &rule, highlightingRules)
	{
        QRegExp expression(rule.pattern);
        int index = expression.indexIn(text);
        while (index >= 0)
		{
            int length = expression.matchedLength();
            setFormat(index, length, rule.format);
            index = expression.indexIn(text, index + length);
        }
    }
    setCurrentBlockState(0);

    int startIndex = 0;
    if (previousBlockState() != 1)
        startIndex = commentStartExpression.indexIn(text);

    while (startIndex >= 0)
	{
        int endIndex = commentEndExpression.indexIn(text, startIndex);
        int commentLength;
        if (endIndex == -1)
		{
            setCurrentBlockState(1);
            commentLength = text.length() - startIndex;
        }
		else
		{
            commentLength = endIndex - startIndex
                            + commentEndExpression.matchedLength();
        }
        setFormat(startIndex, commentLength, multiLineCommentFormat);
        startIndex = commentStartExpression.indexIn(text, startIndex + commentLength);
    }
}